Real-time inertial lower body kinematics and ground contact estimation at anatomical foot points for agile human locomotion

摘要

The ability to accurately capture locomotion is relevant in various use cases, in particular in the sports and health area. With the major goal of providing a measurement system that can deliver different types of relevant information (3D body segment kinematics, spatiotemporal locomotion parameters, and locomotion patterns) in-field and in real-time, we propose a novel probabilistic (single-plane) ground contact estimation method, using four contact points defined through a biomechanical foot model, and integrate this into an existing inertial motion capturing method. The resulting method is quantitatively evaluated on simulated and real IMU data in comparison to an optical motion capture system on walking, running, and jumping sequences. The results show its ability to maintain a good average 3D kinematics estimation error on low- and high-acceleration locomotion, whereas many previous accuracy studies restrict themselves to movements with low to moderate global accelerations, such as upper body activities or slow locomotion. Moreover, a qualitative evaluation of the estimated ground contact probabilities demonstrates the method's ability to also provide consistent information also for deriving spatiotemporal locomotion parameters as well as locomotion patterns (e.g., over-pronation/-supination) simultaneously with the 3D kinematics.